This version returns the particular `FileSystem` that the job's output path belongs to.  I'm not aware of this ever being different than HDFS but I guess it could be?

In *this* case where I have a RecordWriter that's acting as output format for a job, it seems to be more appropriate to get whatever the job is configured for, rather than the `FileSystem.get(conf)` which will be explicitly whatever filesystem the conf is set up for.